Hose or tubular guide catheter

ABSTRACT

A hose or tubular guide catheter which accommodates and guides a balloon catheter through a portion of the vascular system to a site where the balloon catheter can be employed for the dilatation of coronary arteries. The wall of the catheter, in the region of its anterior end, is set back from the edge over a portion of the circumference. If the end of this guide catheter has passed only a little way into the entrance of a coronary artery, blood from the aorta can enter through the large flow section into the catheter and into the coronary artery. Hence the blood supply of the coronary artery is assured. By further advance of the guide catheter, the recess is closed off by the wall of the entrance opening of the coronary artery, so that injected contrast medium will enter full into the coronary artery and cannot pass into the aorta.

This is a continuation of application Ser. No. 635,804, filed on Jan. 2,1991 which is a continuation of Ser. No. 378,525 filed on Jun. 23, 1989.

BACKGROUND OF THE INVENTION

The invention relates to a hose or tubular guide catheter to accommodateand guide a balloon catheter for dilatation of coronary arteries of theheart.

From a printed source due to the firm of Schneider Medintag, Zurich,"Guide catheter with atraumatic tip," "Soft Touch" type, a hose or guidecatheter of the kind in question is known whose end has an annular edgeextending substantially axial to the axis of the catheter. In theimmediate region of its end, the catheter has a more or less curvedform, to facilitate insertion of the end from the aorta into the openingof a coronary artery, or at least render it possible. The guide catheteris moved manually so that its tip will enter a coronary artery andremain there, whereafter a guide wire is passed through the guidecatheter into the coronary artery, and then a balloon catheter isintroduced over the guide wire and through the guide catheter until theballoon arrives in the region of a constriction of the coronary artery,where the balloon, limited in diameter, is inflated and the constrictedplace in the coronary artery is thereby dilated and enlarged.

The diameter of the guide catheter is relatively large so that, withadequate wall thickness, a balloon catheter will pass through. Thiscomparatively large diameter of the guide catheter leads in many casesto its tightly closing the entrance opening of the coronary artery, sothat the blood supply of the coronary artery is blocked. The myocardiumis thereby rendered ischemic with a risk of mortification.

To avoid this disadvantage, the said company print also mentions a guidecatheter having lateral holes at some distance from its tip, throughwhich blood is to enter the guide catheter from the aorta and pass oninto the coronary artery. If these lateral openings are too close to theanterior edge of the guide catheter, there is danger that the openingswill be located in the region of the coronary artery and thus be closedoff by its walls, so that they cannot serve their purpose. If thelateral holes are more distant from the anterior edge of the tip of theguide catheter, blood can indeed flow in, but then there is thedisadvantage that contrast medium to be injected into the coronaryartery through the guide catheter for X-ray visualization of the arterywill leak out of the lateral holes, be lost for purposes of visualizingthe coronary artery, and impede or at least impair the X-ray image byentering the aorta. Besides, there is the disadvantage that the lateralholes tend to be clogged by blood clots.

SUMMARY OF THE INVENTION

The object of the invention is to provide a guide catheter of the kindin question, not subject to the disadvantages portrayed, that is,avoiding interruption of the blood supply to the coronary artery and theloss of contrast medium from the guide catheter into the aorta and atthe same time not losing the desired guiding function.

That object of the invention is accomplished by the teaching specifiedin the characterizing clause of Claim 1.

The fundamental idea of that teaching is to provide the wall of theguide catheter in the anterior region with a slit, which may for examplebe prepared by simply cutting the catheter away laterally. If such aguide catheter is inserted in the entrance opening of a coronary arteryjust so far that the posterior end of the recess or slit is stilllocated within the region of the aorta, than blood can flow from theaorta into the catheter and through it into the coronary artery. In thisinsertion position, the guide catheter can already perform its guidingfunction fully. If contrast media are to be introduced, the guidecatheter may be advanced again briefly so that the recess or slit liesin the region of the entrance opening of the coronary artery throughoutits full length, and is therefore largely closed off by the artery wall.This advance may take place briefly when contrast medium is injected.Then the guide catheter may be withdrawn again somewhat, so that bloodcan again enter as previously described through the recess of the wallof the guide catheter into the coronary artery.

The recess according to the invention may be of equal width inlengthwise direction of the catheter, but having over-all asubstantially greater flow cross-section than the known lateralopenings. The danger of clogging by blood is thereby reduced. However,it is also expedient for the width of the recess to increase towards theanterior edge of the catheter. By thrusting the end of the guidecatheter in to different depths, therefore, the cross section throughwhich blood can flow from the aorta into the coronary artery may bevaried.

Another refinement of the invention consists in that the catheter, inmanner known per se, is made of a more yielding material in the regionof the recess than elsewhere. Through this yieldingness, in the knowncatheter a lateral flexibility and an improved insertion into theentrance opening of a coronary artery is to be achieved. The crosssection of this known catheter does not vary. In the case of thecatheter according to the invention, the recess permits a reduction ofthe cross section of the catheter, so that, according to the shape,width and length of the recess, the catheter may take on a more or lessconstricted or tapered shape, additionally facilitating introductioninto the opening of the coronary artery. Thus the invention not onlyensures blood supply and prevents the loss of contrast medium, but alsofacilitates insertion into the entrance opening of the coronary artery.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be further illustrated with reference to the drawing.

FIG. 1 shows an embodiment of a guide catheter according to theinvention, by way of example, to a small scale,

FIG. 2 shows the end of the guide catheter of FIG. 1, enlarged, in theregion of an aorta and coronary artery,

FIG. 3 shows the exterior end of the catheter of FIG. 1, much enlarged,towards a recess according to the invention,

FIG. 4 is a side view of FIG. 3,

FIG. 5 shows a modification in the representation of FIG. 3, and

FIG. 6 is a side view of FIG. 5.

FIG. 1 shows a guide catheter 1 provided at its posterior end with aconnection 2 and curved in its anterior region firstly in a large arc 3in one direction and secondly in a smaller arc 4 in a differentdirection.

FIG. 2 in particular shows that the extreme end 5 exhibits a recess 6formed by cutting it off obliquely.

The guide catheter 1 is located in an aorta 7, its exterior end 5protruding partly into an entrance opening 8 of a coronary artery 9. Inthis position, the recess 6 has a large access cross-section from theaorta 7, so that blood can flow into the interior of the tubular guidecatheter and on into the entrance opening 8 and the coronary artery 9.In this position as shown, a guide wire as well as a balloon cathetermay already be introduced.

If contrast medium is to be injected, the end 5 of the guide catheter 1can be inserted by suitable manipulation to the left in the drawing andhence into the entrance opening 8 of the coronary artery 9 so that therecess 6 lies entirely within the region of the entrance opening 8. Thisadvancement takes place only briefly during the injection of contrastmedium. Then the end 5 is immediately drawn back into the position shownin FIG. 2, so that blood can again flow in and through, and the bloodsupply of the coronary artery is restored.

FIG. 3 shows the outer tip 5 of the guide catheter 1 in the region ofthe recess 6, the direction of the view being at said recess 6. FIG. 4is a side view of FIG. 3. It will be seen that the wall of the tip 5 isnot cut away straight, but in the form of an S-curve, so that in the topview of FIG. 3 the edge 10 of the recess 6 forms approximately abell-shaped curve. The tip 5 is of a more yielding material than therest of the guide catheter 1. This yielding material is indicated bystippling.

FIGS. 5 and 6 correspond substantially to FIGS. 3 and 4. Like parts aremarked with like reference numerals. The difference is that a recess 10has substantially parallel edges 12, forming a straight slit opentowards the anterior edge of the end 5.

The conformation of the tip of the guide catheter according to theinvention avoids a completely tight closure of the guide catheter at theentrance of the coronary artery. Should a tight closure neverthelessoccur, this will be duly indicated by a pressure drop on the manometer.By retracting the catheter, the flow can be instantly restored withoutlosing the placement of the guide catheter.

The danger of clotting is less with the catheter according to theinvention than for the known catheter with holes, since the guidecatheter has only this one opening, which is flushed as usual. Besides,no contrast medium will be lost into the aorta, since the opening areacan be reduced by displacement, unlike lateral holes, which are notadjustable. A safe operation with reduced danger of ischemia andoptimization of visualization of the coronary arteries by means ofcontrast medium are assured.

I claim:
 1. An intracorporeal guide catheter comprising an elongatedflexible tubular member having proximal and distal ends and a wall whichdefines a single concentric lumen extending the entire wall of saidtubular member and open longitudinally axially at each end thereof, saidwall having at the distal end of the catheter a lateral portion removedtherefrom to thereby provide a gap in said wall extending proximallyfrom the tip of said distal end, with the width of the gap being uniformfor its entire length.
 2. An intracorporeal guide catheter comprising anelongated flexible tubular member having proximal and distal ends and awall which defines a single concentric lumen extending the entire lengthof said tubular member and open longitudinally axially at each endthereof, said wall having at the distal end of the catheter a lateralportion removed therefrom to thereby provide a gap in said wallextending proximally from the tip of said distal end, wherein the widthof the gap bilaterally diminishes symmetrically and non-uniformly alongits length in a bell-shaped pattern.
 3. An intracorporeal guide catheteradapted to guide a dilatation balloon catheter into a coronary artery ofa heart comprising an elongated flexible tubular member having proximaland distal ends and a wall which defines a single concentric lumenextending the entire length of said tubular member and openlongitudinally axially at each end thereof, said wall having at thedistal end of the catheter a lateral portion removed therefrom tothereby provide a gap in said wall extending proximally from the tip ofsaid distal end, with said gap being dimensioned and configured to allowblood flow through the gap from outside of said wall and into said lumenwith the distal end of said catheter being located in said coronaryartery.